<!doctype html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport"
          content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        div {
            box-sizing: border-box;
        }

        .box {
            margin: 0;padding: 0;
            display: flex;
            position: absolute;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            justify-content: space-between;
            width: 200px;
            height: 100px;
        }

        .box .strip {
            width: 15px;
            background-color: skyblue;
            transform-origin: bottom;
            animation-name: scale;
            animation-timing-function: linear;
            animation-duration: 2s;
            animation-iteration-count: infinite;
        }

        .box .strip:nth-child(2) {
            animation-delay: .1s;
        }

        .box .strip:nth-child(3) {
            animation-delay: .2s;
        }

        .box .strip:nth-child(4) {
            animation-delay: .3s;
        }

        .box .strip:nth-child(5) {
            animation-delay: .4s;
        }

        .box .strip:nth-child(6) {
            animation-delay: .5s;
        }

        .box .strip:nth-child(7) {
            animation-delay: .6s;
        }

        .box .strip:nth-child(8) {
            animation-delay: .7s;
        }

        @keyframes scale {
            0% {
                background-color: skyblue;
                transform: scaleY(1);
            }
            50% {
                background-color: transparent;
                transform: scaleY(0);
            }
            100% {
                background-color: skyblue;
                transform: scaleY(1);
            }
        }
    </style>
</head>
<body>
<div class="box">
    <div class="strip"></div>
    <div class="strip"></div>
    <div class="strip"></div>
    <div class="strip"></div>
    <div class="strip"></div>
    <div class="strip"></div>
    <div class="strip"></div>
    <div class="strip"></div>
</div>
</body>
</html>